Cord winding device for window covering

Abstract

A cord winding device for a window covering includes a casing, a reel rotatably mounted on the casing, a torsion spring biased between the casing and the reel, a limit ring secured on the casing and abutting the reel to limit the reel between the casing and the limit ring, and a pull cord attached a bottom of the casing. Thus, the lift cord of the window covering is wound around and stored in the reel of the cord winding device so that the lift cord is rolled up to a higher position to prevent the children from being tangled with the lift cord so as to protect the safety of the children.

1. A cord winding device for a window covering, comprising:
 a casing; 
 a reel rotatably mounted on the casing; 
 a torsion spring biased between the casing and the reel; 
 a limit ring secured on the casing and abutting the reel to limit the reel between the casing and the limit ring; and 
 a pull cord attached a bottom of the casing; 
 wherein the casing has an open side formed with a receiving space to receive the reel; 
 the receiving space of the casing has a bottom wall provided with a pivot shaft; 
 the casing has a periphery provided with a reduced mounting shoulder for mounting the limit ring; 
 the casing has a top formed with a first slot connected to the receiving space; 
 the limit ring is secured on the reduced mounting shoulder of the casing; 
 the limit ring has a top formed with a second slot which is juxtaposed to the first slot of the casing and is connected to the receiving space; 
 the limit ring has an inner portion formed with an exposing hole facing the reel to expose the reel; 
 the reel is rotatably mounted in the receiving space of the casing; 
 the reel includes two stop disks and a spool located between the two stop disks to form a winding space between the two stop disks and the spool; 
 the winding space of the reel is connected to the receiving space of the casing; 
 the winding space of the reel is connected to first slot of the casing and the second slot of the limit ring; 
 the spool of the reel has an open side formed with a receiving chamber to receive the pivot shaft of the casing and the torsion spring; 
 the receiving chamber of the spool has a bottom wall provided with a pivot hole rotatably mounted on the pivot shaft of the casing so that the spool of the reel is rotatable on the pivot shaft of the casing; 
 one of the two stop disks of the reel has a periphery formed with a recessed driving portion exposed outward from the exposing hole of the limit ring; 
 the driving portion of the reel has a bottom wall formed with a hooking hole exposed outward from the exposing hole of the limit ring; 
 the hooking hole of the driving portion is connected to the winding space of the reel and extends through the spool into the receiving chamber of the spool. 
 
     
     
       2. The cord winding device for a window covering of  claim 1 , wherein
 the bottom wall of the receiving space of the casing has a surface provided with a first positioning stub to locate the torsion spring; 
 the bottom wall of the receiving chamber of the spool has a surface provided with a second positioning stub to locate the torsion spring; 
 the torsion spring is mounted on the pivot shaft of the casing and has a first end secured on the first positioning stub of the casing and a second end secured on the second positioning stub of the reel. 
 
     
     
       3. The cord winding device for a window covering of  claim 1 , wherein
 the pivot shaft of the casing is located at a central portion of the casing; 
 the pivot shaft of the casing has a distal end provided with a flexible locking head; 
 the locking head of the pivot shaft has a hook shape and is formed by a plurality of elastic wedges and a plurality of slits disposed between the elastic wedges; 
 the pivot hole of the spool is located at a central portion of the spool and has a peripheral wall locked onto the locking head of the pivot shaft to attach the spool of the reel to the pivot shaft of the casing. 
 
     
     
       4. The cord winding device for a window covering of  claim 1 , wherein
 the reduced mounting shoulder of the casing has a periphery provided with a plurality of elastic locking hooks; 
 the limit ring has a periphery provided with a plurality of locking holes snapped onto the locking hooks of the reduced mounting shoulder to lock the limit ring onto the casing. 
 
     
     
       5. The cord winding device for a window covering of  claim 1 , wherein
 the top of the casing has a surface provided with a first semi-tube surrounding the first slot; 
 the top of the limit ring has a surface provided with a second semi-tube surrounding the second slot; 
 the second semi-tube of the limit ring is juxtaposed to the first semi-tube of the casing to form a tube surrounding the first slot of the casing and the second slot of the limit ring. 
 
     
     
       6. The cord winding device for a window covering of  claim 1 , wherein the bottom of the casing has a surface provided with a hanging hook secured on an upper end of the pull cord. 
     
     
       7. The cord winding device for a window covering of  claim 1 , wherein
 the bottom wall of the receiving space of the casing has a surface provided with provided with an annular support flange; 
 the receiving chamber of the spool is rotatably mounted on and supported by the support flange of the casing.